package bite;

import javax.swing.tree.TreeNode;
import java.util.List;

public class BinaryTree {
    static class TreeNode {
        public char val;
        public TreeNode left;//存储左孩子的引用
        public TreeNode right;//存储右孩子的引用

        public TreeNode(char val) {
            this.val = val;
        }
    }

    public TreeNode createTree() {
        TreeNode A = new TreeNode('A');
        TreeNode B = new TreeNode('B');
        TreeNode C = new TreeNode('C');
        TreeNode D = new TreeNode('D');
        TreeNode E = new TreeNode('E');
        TreeNode F = new TreeNode('F');
        TreeNode G = new TreeNode('G');
        TreeNode H = new TreeNode('H');
        A.left = B;
        A.right = C;
        B.left = D;
        B.right = E;
        C.left = F;
        C.right = G;
        E.right = H;
        return A;

    }

    //前序遍历
    void preOrder(TreeNode root) {
        if (root == null) {
            return;
        }
        System.out.println(root.val + "");
        preOrder(root.left);
        preOrder(root.right);

    }

    //中序遍历
    void inOrder(TreeNode root) {
        if (root == null) {
            return;
        }
        preOrder(root.left);
        System.out.println(root.val + "");
        preOrder(root.right);
    }

    //后序遍历
    void postOrder(TreeNode root) {
        if (root == null) {
            return;
        }
        preOrder(root.left);
        preOrder(root.right);
        System.out.println(root.val + "");
    }


    public int size(TreeNode root) {
        if (root == null) {
            return 0;
        }
        return size(root.left) + size(root.right) + 1;
    }

    public static int learSize;

    // 获取叶子节点的个数
    public void getLeafNodeCount(TreeNode root) {
        if (root == null) {
            return;
        }
        if (root.left == null && root.right == null) {
            learSize++;
        }
        getLeafNodeCount(root.left);
        getLeafNodeCount(root.right);
    }

    public int getLeafNodeCount2(TreeNode root) {
        if (root == null) {
            return 0;
        }
        if (root.left == null && root.right == null) {
            return 1;
        }
        return getLeafNodeCount2(root.left) + getLeafNodeCount2(root.right);
    }

    //获取第k层节点的个数
    public int getKLevelNodeCount(TreeNode root, int k) {
        if (root == null) {
            return 0;
        }
        if (k == 1) {
            return 1;
        }
        return getKLevelNodeCount(root.left, k - 1)
                + getKLevelNodeCount(root.right, k - 1);
    }
    public int getHeight(TreeNode root){
        if (root == null) {
            return 0;
        }
        int leftHeight = getHeight(root.left);
        int rightHeight = getHeight(root.right);
        return Math.max(leftHeight,rightHeight) + 1;
    }
    public TreeNode findVal(TreeNode root,char val){
        if (root == null) {
            return null;
        }
        if (root.val == val) {
            return root;
        }
        TreeNode leftT = findVal(root.left,val);
        if (leftT != null) {
            return leftT;
        }
        TreeNode rightT = findVal(root.right,val);
        if (rightT != null) {
            return rightT;
        }
        return null;
    }
}
